A power module is known from PCT International Patent Publication No. WO 98/15005, in which power transistors are mounted between two DBC (direct bonded copper) substrates having structured CU layers as the wiring level, the fronts and backs of the chips being bonded to the CU layers via a solder layer. If necessary, optional spacer balls may be used to ensure that the solder layer on the structured metal layers on the front of the chips retains an adequate thickness during and after the reflow soldering process. One feature of the DBC substrate is that the CU layers cannot be structured to just any fineness, due to their thickness—typically approximately 300 μm. The CU layer's thickness is necessary to adequately dissipate heat loss from the power chips and to conduct the high currents in the module with as little resistance as possible. As a result, the minimum distance between two CU areas cannot be much smaller than the thickness of the CU layer.